Printing method and apparatus



March 28, 1939. E. ERICKSSON PRINTING METHOD AND APPARATUS Filed April 27, 1936' 3 Sheets-Sheet 1 :J wu mam 5/222? int/mm;

MYLWM/ March 28, 1939. E. ERICKSSON PRINTING METHOD AND APPARATUS 3 Sheets-Sheet 2 Filed April 2'7, 1956 March28,1939. HCKSSON 2,151,960

PRINTING METHOD AND APPARATUS Patented Mar. 28, 1939 v PATENT OFF-ICE 2,151,960. Pmrmc METHOD AND APPARATUS Emil Erlcksson, Chicago, Ill., assignor to Standard Process Corporation, Chicago, 111., a corporation of Delaware Application April 2-1, 1936, Serial No. 76,686. 12 Claims. (Cl. 101-152) This invention relates to printing methods and apparatus, and more particularly to no el means for printing intricate color designs upon relatively thin or flimsy materials such as paper. 5 transparencies, webs formed from regenerated cellulose, and the like. Thepresent application constitutes acontinuationi in part of my application Serial No. 634,406, filed'on September 22, 1932, and entitled Multiple impression printing apparatus. L

In the printing of multiple colors upon textiles, wallpaper and the like, it hasv been the practice in the past to employ two or more color cylinders in combination with a common impression cylinder, an endless belt of hard felt or fabric being provided to travel around the common impression cylinder and around pulleys spaced therefrom. While such arrangements may be suitable for relatively coarse work as encountered in the printing of textiles and wallpapers, they have not been found satisfactory for quality commercial intaglio or Rotogravure color printing such as in the printing of magazines, catalogues and the like, and they have not been found suita- 25 ble for use inconnection with relatively finely made printing rolls such as those engraved by photo-etching methods, the reason for this being that it is impossible to manufacture a belt of rubber-covered'fabric of the required width and [0 thickness or to secure any comparatively hard rubber surface that would be sufficiently uniform in thickness and free of seams, defects and blemishes when the belt has been joined.

With the endless belt as used on textile or wallpaper printing machines, the printing cylinders cannot be placed or spaced around a common impression cylinder as placed on a multi-color Rotogravure printing press according to the present invention. On all such textile and wallpaper L0 machines, the printing impression is disengaged by raising the impression cylinder away from the printing cylinder which makes it necessary to have all the printing cylinders arranged below the center of the commonimpression cylinder. No attempt is made on such printing machines to dry the ink between impressions. Therefore the space between impressions has not been considered important whereas in commercial Rotogravure color printing, it is absolutely necessary 50 to dry between each impression. The printing cylinders are therefore arranged around the common impression cylinder so as to get all possible space between impressions. As in the present invention, impression is released by disengaging 55 the printing cylinders from the common impression'cylinder, it has been found possible to place the printing cylinder above as well as below the center of the impression cylinder. This permits of the use of a common impression cylinder of 'a diameter that is practical in a printing press 5 room.

Further disadvantages of the endless belt arise from slippage on the impression drum or the pulley which is out of the question for close register Rotogravure color work and the natural tendo ency for dirt toaccumulate on the under side of 7 the belt which accumulations make the .im'pression uneven. Y

In the typographical field, it has also been'proposed to arrange a number of printing cylinders 15 around a common impression cylinder. As no drying is necessary between impressions for color process printing in relief, no space is required for this purpose between printing impressions. Therefore, in typographical presses, a

,circumferential surface in that they must be slotted at one or more places to provide means to fasten or tighten the tympan or blanket around the cylindrical form, since the tympan or blanket must be frequently changed. Such a slot or gap invariably comes at amargin where there is no printing, and consequently such an impression 5 cylinder may be used only for typographical or relief printing.

In commercial Rotogravure printing, the essential and criterion of a quality standard product is absolute precision of printing impression. Both the common impression cylinder and the printing cylinders must be in perfect alignment and the accuracy in diameters of the-printing and impression cylinders must be in the order of 0.001 inchto insure absolute uniformity in impression. Such accuracy and the maintenance thereof has not been found possible in the prior art devices. I

In overcoming the aforesaid disadvantages of the prior art and other disadvantages not mentioned, it is a major object 01 the present invention to provide novel printing methods and apparatus wherein the required accuracy of impression can be secured and maintained in order that multi-color printing of paper, transparencies and 5a the like may be accomplished in a commercially practical manner.

A further object of the present invention is to provide a novel common impression cylinder for a multi-color press whereby the material being printed is maintained thereon in perfect register throughout the contact with the various color cylinders, despite any inherent fragility or tendency of the material to warp, shrink or stretch.

Still a further object of the present invention is to provide a novel surface for a common impression cylinder employed in combination with a series of printing cylinders as employed, for

instance, in commercial intaglio or Rotogravure of the colors to be printed on one side of the web, and one or more additional units for printing on the opposite side of the web. Dependent upon the drying method employed between the surface impressions, there is a length of all the way from a minimum of 21 feet to a maximum of 32 feet of partially uncontrolled web between each impression. For this reason it has always been impossible to secure and maintain perfect register on this type of Rotogravure color system, since the web is bound to weave or move sidewise or may shrink or stretch or otherwise change in dimension or possibly warp not only by reason of the application of ink thereto and the drying thereof but also due to the weight of the length of the material.

To overcome this disadvantage of the prior art, it is a further object of the present invention to provide a multi-color press wtih a novel im- Dression surface wherein the web is maintained in close contact with the impression surface throughout all its contacts with the printing cylinders whereby no opportunity is afforded for the web to move sidewise or change in dimension and thus vary the registry of the various colors, despite the flimsy or fragile character thereof.

A further object of the present invention is to provide a novel arrangement of impression and printing rollers whereby the natural static set up in the web is employed to cause the web to cling closely to the impression cylinder and thus maintain the web in perfect register.

Still a further object of the present invention is to provide a novel impression roller in combination'with a printing roller for the multi-color printing of material such as Cellophane, Glassine and the like wherein the inherent characteristics of the material itself causes it to cling tenaciously to the impression cylinder and so insure perfect registry of printing, whereas this same inherent characteristic in such material is a serious handicap and makes it almost impossible to maintain register on the unit type of Rotogravure color press.

A further object of the present invention resides in the provision of a novel common impression cylinder and a method of making it whereby the cylinder surface may be applied and thereafter processed without removing the cylinder from the press.

A further object of the present invention is to provide novel means for use on a press of the type described whereby reconditioning of the surface of'the common impression cylinder may be readily accomplished without disturbing the position of the cylinder in the press.

Still a further object of the present invention is r to provide novel means in connection with a printing cylinder wherebyv there will be no splashing of ink when the roller is operated at relatively high speedsand the vaporization of solvents in the ink will be held to a. minimum.

A further object of the present invention is the provision of novel sealing means for an ink fountain containing a printing cylinder having a doctor associated therewith wherein the sealing means substantially prevents evaporation of the volatile ingredients of the ink with no interference with the action of thedoctor.

Still a further object of the present invention is to provide novel inking means in association with a printing cylinder wherein sustained contact of the cylinder with a continuous supply of fresh ink is assured.

A further object of the present invention is to provide novel stripping means and methods whereby the material being printed is subjected to a stripping action from a printing couple substantially coincident with the printing.

With the foregoing and other objects in view, reference is made to the following description and accompanying drawings wherein:

Figure l is an end view of a printing press illus trating a preferred embodiment of the present invention, a portion of thedrying means and the cylinder operating mechanism being removed.

Figure 2 is an end view taken partially in section of a further preferred embodiment of the present invention in the form of a printing cylinder and the fountain associated therewith as may be employed for the first color in the press of Figure 1.

Figures 3, 4 and 5 respectively are views similar to Figure 2 of the cylinders constituting the second, third, and fourth colors as may be employed in the press of Figure 1.

Figure 6 is a side view of an end plate of the fountain shown in Figure 4 showing a preferred manner of sealing the ends of the printing cylinders.

Figure 7 is a rear elevation taken partly in section of a grinder preferably employed in conditioning the common impression cylinder of the press of Figure 1. v

Figure 8 is a side view of a portion of the pre of Figure 1 with the grinder of Figure 7 shown in operating position;

Referring to the drawings and particularly to Figure 1, a printing press illustrating a preferred embodiment of the present invention is there indicated generally by reference character ll.

Press II is provided with a normally idling common impression cylinder l2 having a suit-- able impression surface l3 formed of a yielding substance such as rubber or the like permanently bonded thereto. While it is to be understood that rubber is preferred, any other resilient or elastic material having equivalent characteristics may be used as a surface for the impression roller. In applying the material to the cylinder, it is not necessary to remove the cylinder from the press, this being a marked advantage inasmuch as said cylinders are of considerable weight and the remove thereof from the press would necessitate the removal of much of the mechanism associated therewith. v

In applying an elastic or resilient material such as rubber to the cylinder, the rubber in the form of sheets is wound around the cylinder to approximately the desired thickness. and substantially sealed from contact with the atmosphere by heat insulating and heat-resistant material such as asbestos sheets and cloth. The cylinder is preferably constructed with a steam chamber I4 either confined to the periphery thereof as shown or occupying the entire interior of the cylinder. Steam of the proper temperature is admitted to steam chamber I through aninlet [5, the water ,of condensation being discharged at i6 whereby the rubber sheeting is vulcanized to the cylinder. After vulcanizing, the heat insulating cover may be removed and the rubber surface ground to the proper size by methods and apparatus to be later described.

Spaced about the entire periphery of common impression cylinder l2 are mandrels or' printing cylinder holders l6, ll, l8 and i9 which are arranged to receive readily removable, thin printing cylinders or shells 2 I held firmly on the mandrel by means described in my application Serial No. 634,406, previously referred to. The shells 2i and the method of forming and utilizing them are fully disclosed and claimed, in my copending apsired, and this arrangement may be varied at a will to produce successive superimposed impressions on thesame area of printing surface from each of the cylinders l6, l1, l8, and [9, by any known printing or transfer means. Different colors or the same color may be printed by each of the cylinders if desired.

As shown in Figure 1, the printing cylinders are preferably positioned both above and below the horizontal axis of the impression cylinder l2 and "are spaced about the entire periphery of the impression cylinder in such a manner that the distance between the linesof printing contact of the first and last, printing cylinders measured along the peripheral surface ofthe impression cylinder in the direction of travel of the web 22 is more than one-half the circumferential distance around the impression cylinder, thus the impression cylinder cannot be moved radially, as

- for replacement purposes, unless one printing cylapplication Serial No; 634,406; Web '22. prior to,

its entry between 'the printing couples formed by the impression surface i3 and the printing cylinders is guided-by pairs of adjustable tensioning rollers 23 and 24 and guide rolls 26 and 21,

all of which are provided with suitable adjusting means as described in my applications above identified. The web 22, afterpassing between the printing couple constituted by impression surface l3 and printing cylinder i3 is guided over astripping roller 28 after which it may be subjected to drying and treating and wound or otherwise conveniently taken care of by any desired means not shown. Particularly in the handling of transparencies such as regenerated cellulose and like relatively flimsy material, it is desired to have the roller 28 located on a tangent to the point of contact between the printing couple formed by arrangement has been found most suitable for stripping the web from the impression cylinder against the static action which tends to hold the web to the cylinder. This action is believed due to the timing of the stripping action substantially with the'application of pressure to the web by cylinder l9 whereby the stripping takes place substantially coincident with a minute displacement of the web relative to the impression cylinder because of the pressure of the printing roller I 9.

As described inmy application Serial 'No. 634,- 406, adjustment means are provided for the various printing cylinders whereby their positions may be adjusted with reference to the impression surface l3 and the cylinders may be either singly or simultaneously thrown out of or into contact with the impression surface. Means for operating several of the adjustment means for the cylinders, inking fountains and doctor blades are shown at 29, such operating means being described in detail in my application hitherto referred to. v

Drying means generally indicated at 3| is disclosed in detail in my application above referred to and no detailed description thereof is considered necessary in the present case, since such does not form part of the present invention.

As will be noted from Figure l, the upper left quadrant 32 of the press frame II is preferably made separate from the remaining portion'of the.

frame and is hinged thereto by suitable pins 33. Cables 34 have ends secured to the quadrant 32 pulleys 36 mountedupon an extended upper portion of the frame as shown at 31 and passing. to suitable means either located within or without the press for retraction purposes. -Thus, if it is desired to gain access to the interior of the press to treat or process the impression surface I3, it is only necessary to retract the cables 34 whereupon. the quadrant 32 will be rotated about pins 33 to a position whereby access may be had to the surface l3 of the common impression cylinder l2.

Ink is supplied to the printing cylinders l6, l1, I8 and i9 through suitable means as described in my application Serial No. 634,406, the excess of inkbeing collected in ahousing positioned around each of the cylinders. As shown in Figure 1, each ink housing 38 comprises generally a trough-like. section closed at the ends by suitable plates and having means as shown at 39 whereby the housingsmay be swung to and away from the printing cylinders. These housings are fully described in my application above re ferred toand no detailed description thereof is deemed necessary in the present case.

Referring to Figures 2 to inclusive, a further illustrated as embodied in the individual color.

printing cylinders and the apparatus associated therewith as shown in Figure 1. As will be noted upon inspection, the ink fountains 4| of each of the individual colors are of generally like design, necessary changes being made in the individual colors as required by the positions of the individual color cylinders with reference to the impression surface I3. Each ink fountain preferably comprises a trough-like section 42 extending from a point adjacent one end of the cylinder to a point adjacent the opposite end of the cylinder. Each trough i2 is designed in a manner to collect the excess ink and to afiord as shown at 35, cables 34 passing over guide I impression surface 13 and the cylinder l9. This means whereby the ink may be returned to a recirculating system such as is described in my applications Serial Nos. 623,421 and 634,406 and is mounted on the press frame II in a manner described in my application Serial No. 634,406 so that ready access may be had to the interior thereof.

From the recirculating system, the ink is supplied to ink distributors generally indicated at 43 which discharge ink onto the surface of the individual printing cylinders. The internal construction of these distributors is described in detail in the applications above referred to and as they form no part of the present invention, a detailed description thereof at the present time is not considered necessary except to state that the ink distributors are modified as the ink fountains to care for the different positions of the printing cylinders I I5, I1, I8 and I9 with reference to the impression surface I3.

As will be noted printing cylinders I6 and I1 are provided with substantially straight distributing plates 44 immediately adjacent the ink distributors while cylinders I8 and I9 are provided with curved plates 45 for a like purpose. Plates 44 and 45 serve to maintain a supply of ink in contact with the surface of the cylinders at all times despite the continual discharge of ink from the distributors, thus insuring a sustained period of contact between the cylinders and fresh ink at all times.

Plates 45 at their forward ends areformed with grooves 49 arranged to.receive a suitable packing material such as a strip of felt. 41 in contact with a portion of the surface of a doctor blade holder 48. The portions of the ink fountains 4| associated with cylinders I8 and I9 adjacent the doctor blade holders 49 are also grooved in like manner as shown at 49 and supplied with a similar sealing or packing strip 5|. Each of the fountain sections with cylinders I8 and I9 is formed with a hinged section 52 at the upper side thereof to aifordready access to the cylinder and the fountain interior, the hinged sections 52 at their forward ends having sealing strips 53 suitably secured thereto by fiat strips 54.

In like manner with reference to cylinders I6 and I1, the lower ends of fountain sections 4| are provided with sealing strips 55 suitably secured to fountain sections 4| as by screws and fastening strips 56. Each fountain section 4| associated with cylinders I6 and I1 has a hinged section 51 secured thereto at the forward end of which is secured a sealing strip 59 adapted to contact portions of the surface of the doctor blade holders 48. It will also be noted that in printing cylinders I6 and I1 adjacent ink distributors 43, sealing strips 59 are provided which contact the printing cylinders and aid in the distribution of ink thereon.

In addition to the trough-like sections 42, the ink fountains 4| comprise end plates 6|, one of which is shown in Figure 6. The various end plates are shaped to fit the various fountains employed in connection with the different printing cylinders. By way of example, an end plate for the fountain of Figure 4 is here illustrated. As shown in Figure 6, each end plate is provided with felt pads or like sealing strips 62 adjacent the cut out portions 60 thereof adapted to receive the cylinder which strips contact the surface of the printing cylinders adjacent the ends thereof. The ink fountains 4| do not extend the entire width of the cylinders I8, I1, I8 and I9, and immediately outside the ends of the foun tain the cylinders are sealed with relation to the fountains by sealing strips 62. If desired, strips 62 may be arranged on the inside of the fountain ends if the design upon the cylinders is such that the printing thereof will not be interfered with. Each strip 62 is secured to its end plate by a curved strip 63 and suitable fastening means 64 passing therethrough.

It will be noted that by reason of the various sealing means and the doctor, the interiors of the ink fountains are substantially sealed against the atmosphere. This not only prevents the access of dust and dirt to the ink but also insures against undue evaporation of the solvents contained in the ink.

With reference to Figures 2 and 5, a detailed view is there shown of the doctor of the present invention. As shown the doctor comprises a metal rod 64 preferably slotted as shown at 65 and provided with a series of apertures 66 and 61 arranged at right angles to one another. A doctor blade 68 is provided in conjunction with a pressure blade 69 which extends to a point approximately one-quarter inch from the edge of the doctor blade 69, the two blades being maintained in superposed relation by being clamped between two elongated plates 1| by suitable screws 12. The plates 1| in turn are held in place by set screws passing through the aperture 66 and are subject to adjustment by set screws operating in apertures 01.

Grinding mechanism Referring back to Figure 1, when the impression surface I3 is first applied or is to be reconditioned, it is necessary after the application and vulcanizing of the elastic or resilient material to grind the surface to a relatively smooth and uniform contour. This is preferably accomplished by a mechanism about to be described.

Referring to Figures '1 and 8, a grinding mechanism is there shown which comprises an under- "carriage '9I fitted with dowel pins or the like 92 which engage corresponding apertures in the press frame, the undercarriage being preferably bolted to the press frame to hold it in the desired position. The carriage 9| is arranged to extend from one side of the frame to the opposite side and in a position parallel to the axis of common impression cylinder I2. The carriage 9| is formed with two aligned apertures 93 and 94 formed in projecting ribs 95 and 95 of the carriage. A shaft 91 is mounted in the apertures in suitable bearings which shaft is suitably connected in driving relation at its right end to a gear 98 through a suitable nut and washer connection 99. Shaft 91 mounts a pulley IOI which is preferably arranged to receive power from the axis of the shaft of the impression cylinder I2 although it is to be understood that it may be driven from an outside source.

A bevel gear I02 is suitably keyed to operate with pulley |0| by a key I03, a corresponding bevel gear I04 being provided on the shaft 91 adjacent the member 95. A diflferential gear I05 is mounted in the carriage 9| (Figure 8) to transmit power from gear I02 to gear I04. Both gears I02 and I04 are mounted to rotate freely on shaft 91.

Secured to gears I02 and I04 and arranged to rotate therewith are clutch elements I09 and I01 respectively, these elements being arranged to engage "a. clutch element I00 slidably mounted on shaft 91 and splined thereto so as to rotate with the shaft. Fork I09 with a suitable operating bar I is connected with clutch element I09 to slide the same on the shaft 91.

A threadedshaft H2 is mounted on suitable bearings in elements 96 and 96 and mounts a a suitable collar II'I thereon having threads engaging with a threaded portion II 8 of shaft H2.

From the structure thus far described, it will be noted that upon rotation of pulley I6I in clockwise direction, gear Ifl2 will be revolved in the same direction. Ifthe clutch element I68 is moved to the right so that it engages clutch element I06 secured to gear I02, shaft 91 will likewise be driven in av clockwise direction and gears 98 and H3 will drive shaft II2 to move the table or carriage II6 to the left.

If the clutch element I08 be moved to the left to engage clutch elementIIlI, the shaft 91 will be driven through bevel gear I64 in counterclockwise direction thus causing rotation of shaft H2 in a clockwise direction moving the table I I6 to the right. 'It is thus seen that means is provided for quickly and easily reversing the direction of travel of the table II6 by relatively simple mechanism. I

Table H6 is suitably grooved as shown at II9,

- the left side of the groove being provided with adjustable member I2I to permit locking of the table in the groove.

A second table I22 is formed with guide members I23 arranged to fit within groove H9 and slide therein. To-eifect sliding movement of table I22 relative to table II6, a threaded shaft I24 is provided which engages threaded member I25 secured to table H6 and is held in relatively fixed relation to table I22 by a collar I26 as shown in Figure 8. A supporting frame I2I is secured to table I22 as by bolts I28, frame I21 having upstanding portions I29 and I3I which support bearings I32 and I33 respectively. Bearings I32 and I33 are identical, each being provided with a roller element I34-secured in place by collars I35 and I36 and bolts I31 and I38, suitable lubricant seals I39 being provided.

A shaft MI is mounted to rotate in bearings I32 and I33, theshaft having a pulley I42 keyed to the left end thereof and a suitable grinding wheel I43 secured to the right end thereof. An electric motor I44 is mounted on the rear of table I22 as shown in Figure 9, and is arranged to drive pulley I42 through a suitable connection as by belt 145.

By raising the sector 32 of press II as shown in Figure 1 through the use of cables 34, approximately a quadrant of the impression surface I3 is open to access. The grinding mechanism of smooth and accurate surface is easily accomplished. It will be noted that this grinding is possible without dismantling the press.

While the grinding attachment as disclosed herein has been described in connection with a press having a pivotal section, it is to be understood that the use of the grinding attachment is not so limited. On presses that are built without the pivotal section, the grinding attachment substantially as described herein may be bolted or similarly secured to either a planed pad on the frame of the press or to a bracket that can be bolted or otherwise fastened to the frame.

The press of the present invention has been found to be particularly valuable in the printing of relatively fragile and flimsy transparent material such as transparent regenerated cellulose and like materials. This is believed to be due in part to the condenser action on the layer I3 of elastic or resilient material and the metal common impression cylinder I2, the material as soon as it contacts the impression cylinder becoming statically charged and clinging to the impression cylinder as if glued thereon. It is thus possible to print very accurately thereon and obtain a. registration of different colors to a degree not hitherto considered possible. No matter how delicate or fragile the web may be, it is impossible for the material to be torn or the registration of color thereon to become inaccurate once the printing rolls have been properly adjusted. The characteristic of the material adhering tightly to the impression cylinder prevents any change in dimension thereof as might be occasioned by shrinkage due to contact with the ink or heat from the driers.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A printing press for Rotogravure or intaglio multi-color printing comprising a common impression cylinder provided with a web contacting surface permanently bonded thereto and a plurali-ty of printing cylinders spaced about said impression cylinder, said contacting surface being formed as a continuous surface of elastic or retacting surface comprising a metal base and a.

continuous precision ground layer of elastic or resilient material permanently bonded thereto.

3. A printing press for Rotogravure or intaglio multi-color printing comprising a common im-' pression cylinder provided with a web contacting surface, and a plurality of printing cylinders spaced about said impression cylinder, said contacting surface comprising a metal base with'a continuous precision-ground layer of rubber vulcanized thereto.

4. An impression cylinder for use as a common impression cylinder for a plurality of printing cylinders in Rotogravure or intaglio printing comprising a cylinder having a metal surface thereon and a layer of resilient or elastic material permanently bonded thereto, said material being ground to precision to form a smooth continuous cylindrical surface.

5. An impression cylinder for use as a common impression cylinder for a plurality of printing cylinders in Rotogravure or lntaglio printing com-' prising a cylinder having a metal face and a layer of rubber vulcanized thereto, said rubber being precision-ground to form a continuously smooth cylindrical surface. I

6. In a multicolor printing press of the type defined in claim 1, a stripping roller disposed adjacent the region at which the final printing operation takes place, said roller being so located as to cause the web to leave the surface of said impression roller upon a line which is substantially tangential to the surface of said impression cylinder at that printing region.

7. A printing prom for Rotogravure or multicolor intaglio printing comprising a common impression cylinder, a continuous layer of resilient material permanently bonded to the periphery of said cylinder to provide a web-contacting surface, and a plurality of printing cylinders spaced about the entire periphery of said impression cylinder.

8. A printing press for Rotogravure or multicolor intaglio printing comprising a normally idling common impression cylinder having a continuous, resilient precision -formed peripheral surface permanently bonded thereto about the major portion of which a web to be printed is wrapped in close contact, and a plurality of spaced driven printing cylinders adapted to firmly contact spaced portions of said web about the periphery of said impression cylinder, said impression cylinder being frictionally driven by said printing cylinders.

9. A printing press for Rotogravure or multicolor intaglio printing comprising a normally idling common impression cylinder, a continuous, resilient precision-formed web-contacting surface permanently bonded to the periphery of said cylinder, and a plurality of driven printing cylinders' spaced about the entire periphery of said imprassion cylinder, said impression cylinder being frictionally driven by one or more of said printing cylinders.

10. A printing press for Rotogravure or intaglio printing comprising a common impression cylinder having a continuous, resilient, precision ground peripheral surface permanently bonded thereto about which a web to be printed is wrapped in close contact for more than. half the circumferential distance around said impression cylinder, and at least three printing cylinders adapted to firmly contact spaced portions of the web about the periphery of said impression cylinder, said printing cylinders being spaced about the entire periphery of said cylinder in such a manner that the impression cylinder cannot be displaced radially without shifting at least one of said printing cylinders.

11. A printing press for Rotogravure or intaglio printing comprising a common impression cylinder having a continuous, resilient, precision ground peripheral surface permanently bonded thereto about which a web to be printed is wrapped in close contact for more than half the circumferential distance around said impression cylinder, the surface of contact between said web and impression cylinder including the bottom half of the peripheral surface of said impression cylinder, a plurality of printing cylinders adapted to firmly contact spaced portions of said web along said bottom half of the impression cylinder surface and at least one printing cylinder adapted to engage said web along the upper half of the peripheral surface of said impression cylinder, said points of contact and engagement being such that said impression cylinder cannot be displaced radially without shifting at least one of said printing cylinders.

12. A printing press for Rotogravure or intaglio printing comprising a common impression cylinder having a smooth, resilient, continuous web contacting peripheral surface permanently bonded thereto, a plurality of spaced printing cylinders having parallel axes disposed about the peripheral surface of said impression cylinder below the horizontal axis thereof and a plurality of printing cylinders whose axes are parallel to each other and to the axes of the above mentioned cylinders disposed about the peripheral surface of said impression cylinder above the horizontal axis thereof, said printing cylinders being adapted to print in succession upon a web wrapped about the peripheral surface of said impression cylinder for more than half the circumference thereof, said printing cylinders being arranged so that said impression cylinder cannot be displaced radially without shifting at least one of said printing cylinders.

' EMIL ERICKSSON. 

